Comparison of methods for isolation of bacterial and fungal DNA from human blood.

The study aimed at optimization of DNA isolation from blood of representatives of four microbial groups causing sepsis, i.e., Gram negative: Escherichia coli, Gram positive: Staphylococcus aureus, yeast: Candida albicans, and filamentous fungus: Aspergillus fumigatus. Additionally, the five commercial kits for microbial DNA isolation from the blood were tested. The developed procedure of DNA isolation consisted of three consecutive steps, i.e., mechanical disruption, chemical lysis, and thermal lysis. Afterward, DNA was isolated from the previously prepared samples (erythrocyte lysis) with the use of five commercial kits for DNA isolation. They were compared paying heed to detection limit, concentration, DNA purity, and heme concentration in samples. The isolation of DNA without preliminary erythrocyte lysis resulted in far higher heme concentration than when lysis was applied. In the variant with erythrocyte lysis, two of the commercial kits were most effective in purifying the DNA extract from heme. Designed procedure allowed obtaining microbial DNA from all four groups of pathogens under study in the amount sufficient to conduct the rtPCR reaction, which aimed at detecting them in the blood.

Haematological changes in rabbits (Oryctolagus cuniculus f. domesticus) in the course of pregnancy.

The analysis of haematological parameters is an important element of the assessment of the physiological condition of animals. Haematological parameters may change both under the influence of various external factors, and in the course of normal pregnancy, which has been found in various species of mammals, including rabbits. Our study showed statistically significant (p<0.05) changes in basic haematological parameters: RBC (decrease; 5.87±0.48 at day 15 vs. 5.42±0.32 T/L at day 26), MCH (increase; 1.35±0.04 before matching vs. 1.41±0.03 fmol at day 26), RDW (decrease; 15.77±1.80 at day 15 vs. 14.27±1.57% at day 26) MPV (increase; 5.17±0.31 at day 15 vs. 5.92±0.70 fL at day 26), WBC (decrease; 8.60±2.57 at day 15 vs. 4.94±0.88 G/L at day 26) and PLT (decrease; 398.17±91.67 before matching vs. 271.67±61.72 G/L at day 26) in Termond White rabbits and RBC (decrease; 6.18±0.68 before matching vs. 5.68±0.54 T/L at day 26), Hb (decrease; 8.00±0.90 before matching vs. 7.32±0.71 mmol/L at day 26), MCH (decrease; 1.32±0.05 at day 15 vs. 1.29±0.04 fmol at day 26) and WBC (decrease; 9.62±1.81 before matching vs. 5.85±2.23 G/L at day 26 as well as 9.58±2.35 at day 15 vs. 5.85±2.23 G/L at day 26) in Popielno White rabbits. Moreover, in the Popielno White rabbits we recorded a significant (p<0.05) decrease in the percentage of irregular erythrocytes at the end of pregnancy (11.00±10.02 at day 15 vs. 3.00±4.94 at day 26). The changes appear to be physiological but should be considered in studies using rabbits as model organisms.